Semi-skeletal molecular model assembly



y 1970 G. c. BRUMLIK 3,509,642

SEMI-SKELETAL MOLECULAR MODEL ASSEMBLY Filed Sept. 13, 196'? 4Sheets-Sheet 1 ATTORNEY May 5, 1970 G. c. BRUMLIK SEMI-SKELETALMOLECULAR MODEL ASSEMBLY 4 Sheets- Sheet 2 Filed Sept. 13, 1967 FlG.

ATTORN EY May 5, 1970 s. QBRUMLIK 3,509,642

SEMI-SKELETAL MOLECULAR MODEL ASSEMBLY Filed Sept. 13, 1967 4Sheets-Sheet 5 INVENTOR. GEORGE C. BROMLI K ATTORNEY y 5, 1970 G. c.BRUMLIK 3,509,642

SEMI-SKELETAL MOLECULAR MODEL ASSEMBLY v Filed Sept. 13, 1967 4Sheets-Sheet 4 INVENTOR. GEORGE c. BRUMLIK ATTORNEY United States Patent0 M 3,509,642 SEMI-SKELETAL MOLECULAR MODEL ASSEMBLY George C. Brumlik,154 Upper Mountain Ave., Montclair, NJ. 07042 Filed Sept. 13, 1967, Ser.No. 667,581 Int. Cl. G09b 23/26 US. Cl. 35-18 8 Claims ABSTRACT OF THEDISCLOSURE A molecular model assembly including a plurailty of unitsrepresenting atom cores and having solid bodies formed as tetrahedrons,trigonal bipyramids and octahedrons, with a bore formed at each cornerof each body and arranged in accordance with the symmetry axes ofvalence orbitals and bond angles of the atom to be depicted by the body.A plurality of elongated rods are also provided for interconnecting theatom core units to form semi-skeletal models of selected molecules, andthe assembly also includes spherical bodies representing terminal atoms,ellipsoid bodies representing orbital lobes, and bodies of bulbous,eccentric shape representing antibonding orbital lobes, these bodiesbeing adapted to be mounted on the interconnected atom core bodies tocomplete the assembled molecular model.

The present invention relates to model assemblies used to representatoms and molecules, particularly models representing the physical andgeometric relationships of molecular and atomic orbitals.

In my prior US. Patent No. 3,080,662 issued Mar. 12, 1963, I have shownand described a molecular model assembly in which the atoms weredepicted by solid spherical elements having appropriately locatedopenings frictionally reciving pins by means of which these elementswere interconnected. These openings are positioned and directed inaccordance with the orientation of the symmetry axes and the symmetryplanes of atomic and molecular orbitals. The atoms and their orbitalsare depicted in the models of this patent in three dimensional form, andthe models can be designated as space-filling."

In another US. Patent No. 3,333,349 issued Aug. 1, 1967, I have shownand described a molecular model assembly in which the atoms and theirorbitals are represented in open framework form. In particular, theatoms are represented as valence clusters by the use of multiarmcoupling units having arm sections angularly arranged to represent thesymmetry axes of atomic valence orbitals and bond angles.

While the models assembled by the structures disclosed in theaforementioned patents provide an accurate representation of thecharacteristic shapes, volumes and spacial orientation of atomic andmolecular orbitals in accordance with modern theories of valence, theylack a garphic depiction of the atoms insofar as their symmetry axes andplanes are concerned, which visual representation may be of great use tothe student. The aforementioned framework model depicts the atom only asa valence cluster. The space-filling model depicts the atom as a sphere,which, while in accordance with prevailing theory, does not illustratethe symmetry planes.

It is an object of the present invention to provide molecular orbitalmodels in which the atoms are made in the form of polyhedrons to depictthe tetrahedron, trigonal bipyramid and octahedron patterns constitutingthe three basic forms of angles for virtually all atoms.

Another object of the invention is the provision of molecular orbitalmodels in which the solid atoms in polyhedron form are coupled byframework connectors 3,509,642 Patented May 5, 1970 to provide asemi-skeletal type model presenting a more apparent visual indication ofthe state of centers of the atoms and their states of hybridization.

Still another object of the invention is the provision of molecularorbital models of the character described in which the molecules can beshown not only in a static state but in an excited state, and therelative motions of atoms within a molecule can be depicted.

In accordance with the invention there is provided a model assembly forrepresenting the atomic and molecular orbital structure of atoms in amolecule, which assembly includes a plurality of units representing atomcores and each constituting a solid body having the form of atetrahedron, trigonal bipyramid or octahedron, with a bore at eachcorner thereof arranged in accordance with the symmetry axes of valenceorbitals and bond angles of the atom to be depicted by the unit. Theassembly also includes a plurality of units representing atomic orbitallobes, each of which units comprises a hollow body of generallyellipsoid shape having a terminal bore, as well as a plurality of hollowspherical units representing terminal atoms. In addition, the assemblyincludes coupling means in the form of elongated members having endportions sized to fit frictionally within the bores of the atom coreunits and orbital lobe units for interconnecting selected atom coreunits and for connecting selected orbital lobe units and sphericalterminal atom units to said atom core units to form semi-skeletal modelsof selected molecules.

Additional objects and advantages of the invention will become apparentduring the course of the following specification when taken inconnection with the accompanying drawings, in which:

FIGS. 1, 2 and 3 respectively are perspective views of three differentembodiments of atom core bodies employed in the models of thisinvention;

FIGS. 4, 5 and 6 respectively are elevational views of three dilferentsizes of hexagonal coupling rods which may be employed to interconnectthe core bodies to each other or to orbital lobe bodies;

FIG. 7 is an elevational view, partially broken way, of a flexiblecoupling rod which may be employed in the model assembly;

FIG. 8 is an exploded elevational view of another form of coupling rodassembly which may be employed for interconnecting the core bodies toeach other or to orbital lobe bodies;

FIG. 9 is a perspective view of an alternate form of the tetrahedroncore body shown in FIG. 1;

FIG. 10 is an isometric view showing two of the core bodies of FIG. 1coupled together to depict two carbon atoms in a single bond;

FIG. 11 is an isometric view of an assembled model depicting theframework of the three carbon atom cyclopropane ring;

FIG. 12 is an isometric view of an assembled model depicting an ethanemolecule and including spherical terminal bodies;

FIG. 13 is an enlarged cross sectional view of one of the sphericalelements depicting a terminal atom body, as taken along line 1313 ofFIG. 12;

FIG. 14 is an isometric view of a space-filling element representing anorbital lobe;

FIG. 15 is an isometric View of an assembled model depicting a benzenering with a ground state molecular orbital;

FIG. 16 is an isometric view of an assembled model depicting a benzenering with an excited molecular state orbital;

FIG. 17 is an isometric view of a space-filling model element depictingthe lobe of an anti-bonding orbital; and

FIG. 18 is an isometric view of an assembled model of ethylene havinganti-bonding orbital lobes.

Referring in detail to the drawings and particularly to FIGS. 1-3, thereis shown a series of three different shapes of covalent core bodies 20,22 and 24 which are employed to depict bonding atoms in the molecularmodels of the present invention. All three bodies 20, 22 and 24 areformed in the shapes of polyhedrons and may be molded of plasticelastomer or other suitable material.

The core body 20, shown in FIG. 1, is in the form of a tetrahedron andhas bores 26 formed at each of its corners and extending toward thecenter of the body, to provide an sp. tetrahedral pattern representingthe symmetry axes of the atomic valence orbitals of a representativeatom.

The core body 22, shown in FIG. 2, is in the form of a trigonalbipyramid, and is also provided with centrally-extending bores 28 ineach of its corners, providing a trigonal bipyramid pattern representingthe symmetry axes of the atomic valence orbitals of an atom having sp.or d.sp. hybridization.

The core body 24, illustrated in FIG. 3, is in the form of anoctahedron, and is again provided with centrallyextending bores 30 ateach of its corners to represent the octahedral pattern of the symmetryaxes of atomic valence orbitals of an atom having sp. or df sp.hybridization.

The core bodies 20, 22 and 24 thus represent the threedimensional bodiesof bonding atoms, while their respective bores 26, 28 and 30 representthe angular orientation of the atomic valence orbitals in space. Theplanar faces of these polyhedron core bodies, terminating at finitecorners, give an instant and graphic representation of the symmetryangles and planes of the particular atom when viewed within an assembledmodel. It will be appreciated that all three bodies 20, 22 and 24 haveequilateral triangular faces of the same size, which is desirable andimportant for purposes of instruction.

The purpose of the bores 26, 28 and 30 is to receive one end of acoupling rod such as the rod 32 shown in FIG. 4. This rod 32 has arelatively short central shank 34 of hexagonal cross-section, whichterminates at both ends in cylindrical sections 36 of reduced diameter.The reduced cylindrical end sections 36 are sized for frictionalinsertion within the bores 26, 28 and 30 of the respective core bodies20, 22 and 24, the elastomeric nature of the bodies providing tightgripping engagement upon these end sections. Thus, one end section ofthe coupling rod 32 may be firmly but removably mounted with the bore ofone core body and its other end similarly mounted in a bore of anothercore body for assembling two bodies in position to represent a moleculeor a portion thereof. The shank 34 is made of hexagonal shape to providean effective finger grip whereby the coupling rod may be twisted formounting and removing the same from the core bodies. In addition, theshank is made relatively short to depict a triple bond distance.

FIG. shows a coupling rod 38, which is identical to the rod 32 of FIG.4, except that its hexagonal central shank 40 is of greater length torepresent the greater bond distance characteristic of a double bond.

FIG. 6 illustrates another coupling rod 42 which is identical to therods 32 and 38 except that its hexagonal central shank 44 is stilllonger, representing the even greater bond distance of a single bond.

The coupling rod 46 illustrated in FIG. 7 differs from those previouslydescribed in that its shank 48 is flexible and can be bent to depict adynamic rather than a static model in which various relative motions ofatoms within a molecule are shown. Then bending of such coupling rod mayalso be employed to illustrate stretching of bonds, as well as thephenomenon known as scissoring wherein two atoms move together and passeach other. To afford such bending capabilities, the shank 48 is made inthe form of a tightly-coiled spring terminating in cylindrical sec ion50 identical to the s c ons 36 pre io y escribed in that they are sizedfor insertion within the bores of the core bodies shown in FIGS. 1-3.

FIG. 8 illustrates a modified type of coupling which may be employed inthe assembly of the core bodies into models. In this instance thecoupling member comprises a pair of metal elements 52 and a length ofplastic tubing 54. Each metal element 52 is formed of a pin 56 having aflange or disc 58 integrally formed at its center. The pin 56 is sosized that one end thereof may be frictionally inserted into a bore 26,28 or 30 of one of the core bodies of FIGS. l-3, until the flange 58engages the end of the bore and prevents further insertion. The oppositeend of the pin 56 now projects from the corner of the core body, and thelength of plastic tubing 54 can now be inserted and frictionallyretained upon this projecting end. Thus, where the pair of couplingmembers are inserted into two respective core bodies, they may be joinedby the length of plastic tubing 54, which may be cut to appropriate sizeto represent the bond in exact scale. The tubing may be made of aflexible plastic to permit bending in the manner of the coupling rod 46shown in FIG. 7.

Another manner in which coupling of the core bodies may be accomplishedis shown in FIG. 9, wherein a tetrahedron core body 20a, correspondingto the core body 20 of FIG. 1, is illustrated by way of example. In thisinstance, the core body 2011 is formed with a metal or plastic pin 60fixedly molded Within each of the bores at the corners of the core body,or integrally molded as a projection of the core body. The pins 60 thusproject from each corner of the body along respective axes which passthrough the central point of the body, thus extending in directionsrepresenting the symmetry axes of the atomic valence orbitals. Theprojecting pins 60 of different core bodies may be coupled together bylengths of plastic tubing 62 similar to the tubing lengths 54 of FIG. 8.The tubing 62 is preferably made of elastomeric plastic, and may be cutto appropriate size depending upon the type of bond to be depicted.

FIG. 10 shows an assembled model consisting of tWo core bodies 20 oftetrahedron shape with a coupling rod 42 of the type shown in FIG. 6inserted within a core of each body, in the manner previously described.The model thus may represent two bonded carbon atoms, with the couplingrod 42 representing the direction and scale length of a single bond.

FIG. 11 illustrates a model representing a cyclopropane carbon skeleton.In this model, a carbon ring is formed of three of the core bodies 20arranged in a circular pattern and interconnected by flexible couplingrods 46 in the manner shown. The coupling rods 46 are bent to form thecarbon ring, and it will be appreciated that the elastomeric plastictubes 54 or 62 of FIGS. 8 and 9 may be also employed with theircorresponding fastening elements to serve the same purpose.

While the core bodies shown in FIGS. 1-3 and previously described, areprovided to represent the central interconnected atoms of molecules, thegeometric shapes thereof are not significant in the depiction ofterminal atoms of molecules. Consequently, different elements areprovided for representing such terminal atoms, these having contrastingshapes to visually distinguish from the central atoms. By way ofillustration, FIG. 12 shows a model representing a molecule of ethaneand including two central carbon atoms having core bodies 20 oftetrahedron shape connected by a coupling rod 42. The model alsoincludes six core bodies 64 representing terminal hydrogen atoms. Thebodies 64 are made of spherical shape as shown, and are preferablymolded in hollow form as shown in the sectional view of FIG. 13. Eachspherical core body 64 is formed with an integral tubular neck 66defining a through bore 68 sized for frictional mounting on the end of acoupling pin 70. The pins 70 are sized for insertion into and frictionalretention within the appropriate bores 26 of the central core bodies 20.The spherical core bodies 64 are made hollow so as to be light inweight, whereby a number of these terminal bodies may be mounted on asingle central body without undue stress. In addition, while thespherical shape illustrated is chosen to distinguish the terminal atomsfrom the central atoms, the terminal atoms may be made of other selectedshapes, for example spheroconical shapes to represent more accuratelythe actual shape of the atoms.

The models shown herein are also adapted to include representation ofvolume orbitals in the nature of orbital lobes which protrude from thecovalent cores and contribute to the atomic volume beyond the volume ofsaid cores. Such orbital lobes exist where an atom is unsaturated or hasnon-bonding valence electrons, and assume characteristic shapes, volumesand spacial orientations. In FIG. 14, a hollow body 66 is showndepicting an unshared electron pair orbital. The body 66 is of ellipsoidshape to represent generally the geometric shape of the orbital lobe inaccordance with prevailing theories, and is formed with a tubular neck74 having a through bore 76 sized to frictionally receive an end of oneof the Coupling pins 70 so that the lobe body 66 may be mounted upon oneof the atom core bodies.

FIG. 15 illustrates the use of a plurality of the orbital lobe bodies 72in an assembled model. The model shown depicts a benzene ring and isformed of six trigonal bipyramid core boodies 22 interconnected by acorresponding number of coupling rods 42, representing sigma bonds, andarranged in the form of a hexagon. Each n core body 22, representing acarbon atom, has mounted at the top thereof a lobe body 72 by means of arespective coupling pin 70 inserted in the bore 28 of the top corner.Similarly, each core body 22 also has mounted at the bottom cornerthereof a lobe body 72a which is identical in size and shape to the lobebody 72 except that it is differently colored or shaded. The upper groupof lobe bodies 72 schematically represent an overlap of atomic orbitalsto indicate the formation of a single upper orbital streamer which intheory is annular. Similarly, the lower group of lobe bodies 72aindicate the formation of a continuous lower orbital streamer. Thus allof the upper lobe bodies 72 are uniformly shaded or colored to indicatethe same sign or phase of the wave function in the region of the upperstreamer, and all of the lobe bodies 72a are also uniform but of adifferent color or shade to indicate a common sign or phase of the Wavefunction in the region of the lower streamer, which is the opposite ofthe sign of that of the upper streamer. This uniformity of wave functionsign in the two streamers is characteristic of a ground state in themolecule of benzene.

FIG. 16 shows a model in which the same parts are rearranged to depict abenzene ring with an excited state molecular orbital. In this view, theupper orbital lobes are represented by alternating bodies 72 and 72awhile the lower lobe bodies 72 and 72a alternate with the upper bodies.This alternate lobe shading indicates reverse phases of atomic orbitalwave functions above and below each atom, which demonstrates theinability of the atomic orbitals to form uniform annular streamers aswere present in the ground state. This is characteristic of anelectronically excited state in the molecule.

For the representation of the lobe of an anti-bonding orbital, the lobebody 80, shown in FIG. 17 is provided. This lobe body 80 is of thebulbous, eccentric teardrop shape shown, and terminates in a tubularneck 82 having a bore 84 for receiving a coupling pin. The lobe bodies80 can thus be mounted on the atom core bodies in the same manner as thelobe bodies 72, previously described.

The anti-bonding orbital lobe bodies 80 are used, for example, in themanner shown in FIG. 18, wherein a model of an ethylene molecule isshown. The model comprises two core bodies 22, connected by a couplingrod 42 and representing two carbon atoms in the sp. hybridized form. Alobe body is connected by a coupling pin 70 to the upper and lowercorner of each of the core bodies 22 as shown in FIG. 8. A model of thistype has significant predictive value in indicating for instance, whatwill occur in the molecule when the latter is exposed to ultra-violetlight, or the shape which the molecule will assume when electronicallyexcited.

The mode elements described above have additional practical predictivevalues in their ability to correlate the physical and chemicalproperties of materials with the geometries of not only ground states ofmolecules, but excited states as well, a :property not found in existingmolecular models or assemblies.

While preferred embodiments of the invention have been shown anddescribe-d herein, it is obvious that numerous omissions, changes andadditions may be made in such embodiments without departing from thespirit and scope of the invention.

What is claimed is:

1. A model assembly for representing the atomic and molecular orbitalstructure of atoms in a molecule, said assembly comprising a pluralityof units representing atom cores, each of said units comprising a solidbody having the form of a polyhedron with triangular planar faces andwith a bore at each corner thereof arranged in accordance with thesymmetry axes of valence orbitals and bond angles of the atom to bedepicted by said unit, the bodies of said plurality of atom core unitsbeing of three types respectively defining a tetrahedron, a trigonalbypyramid and an octahedron depicting the forms of the hybridizationstates of a single atom, a plurality of units representing atomicorbital lobes and each comprising a hollow body of substantiallyellipsoid shape having a terminal bore, and coupling means in the formof elongated members having end portions sized for frictional mountingwithin the bores of said atom core units and orbital lobe units forinterconnecting selected atom core units and for connecting selectedorbital lobe units to said atom core units to form semi-skeletal modelsof selected molecules including scale representations of bond angles,bond distances, atomic orbitals and internuclear distances, with themolecules shown in ground states and excited states.

2. A model assembly according to claim 1 in which said atom core bodiesare made of elastomeric material and said coupling means includes aplurality of coupling rods for interconnecting said atom core units,said coupling rods each having a central shank of polygonalcross-section and terminal cylindrical end portions sized to fitfrictionally within the corner bores of said atom core units, thecentral shanks of said coupling rods being respectively sized torepresent to scale the bond distances of single bonds, double bonds andtriple bonds.

3. A model assembly according to claim 1 in which said coupling meansincludes a plurality of elongated members having flexible central bodyportions capable of bending in the assembled model to depict a dynamicmolecular condition.

4. A model assembly according to claim 1 in which said coupling meansincludes a plurality of pins sized for insertion within the corner boresof said atom core units, and an elongated tubular member of bendableplastic material sized to frictionally receive one of said pins in eachend thereof.

5. A model assembly according to claim 1 in which the body of each ofsaid atom core units is formed with a pin projecting from each cornerthereof along an axis extending through the center of the polyhedroncore unit body, and in which said coupling means includes an elongatedflexible tube of sufiicient internal diameter to be frictionally mountedon said pins.

6. A model assembly according to claim 1 which also includes a pluralityof hollow spherical bodies sized to represent terminal atoms, each ofsaid bodies having a neck portion containing a bore sized tofrictionally receive one of said elongated coupling members, wherebysaid spherical body may be connected to one of the corner bores of anatom core unit.

'7. A model assembly according to claim 1 in which said orbital lobeunits are differently shaded to represent opposite polarities to depictin the assembled models ground state and excited state orbitals.

8. A model assembly according to claim 1 in which said plurality oforbital lobe units include units of bulbous, eccentric ellipsoid shape,to represent lobes of antibonding orbitals.

References Cited UNITED STATES PATENTS 8 3/1932 Dodge 35-18 2/ 1944Brenneman 4626 X 12/1959 Parker 46 26 X 1/ 1960 Subluskey 3518 8/1967Brumlik 35-18 FOREIGN PATENTS 10/1966 Germany.

US. Cl. X.R.

